SEXUALITY IN BACTERIA III 



The resting nucleus may be formed directly from the secondary nucleus, 

 with or without the intervention of a sexual process, hi the case of Bad. 

 ftiahaccamm, described by Stoughton, the microcyst is extruded from the 

 point oi contact of the conjugating cells, or from the side of the bacterium 

 when conjugation is not apparent. As the microcyst grows the mother cells 

 shrink, and eventually disappear. This lateral extrusion of the microcyst 

 has been reported in Bacteriacea' by Mellon (1925), but the cytological processes 



{After Stoughton. Reproduced from the Proceedings of the Royal Society.) 



Fig. 49 

 MATURATION OF THE RESTING CELL IN BACT. MALV ACE ARUM 



The microcyst is formed from the secondary nuclear phase, and is extruded laterally 

 from the mother cell. 



which accompanied it were not described. It is apparently no more than a 

 variant o£ the commoner process of direct transformation o^ the vegetative 

 cell. 



F: SEXUALITY IN MYCOBACTERIA 



(21, 22, 24, 25) 



Among the many accounts oi morphological development cycles in 

 M. tuberculosis, only that of Lindegrcn and Mellon (1932, 1933) gives a con- 

 vincing description of the accompanying cytological phenomena. It is 

 interesting to observe, however, that it includes a sexual process, in the 



